The present invention pertains to a process for the preparation of an intermediate chemical compound useful for preparing herbicides. More specifically, the present invention pertains to an improved process for preparing 4,6-dimethoxy-2-((phenoxycarbonyl)amino)-pyrimidine (hereinafter "DPAP") which is useful as an intermediate for the preparation of sulfonylurea herbicides.
Intermediates for herbicides are preferably free of substantial amounts of impurities especially impurities which will be carried through to the final herbicide itself. Impurities in agricultural products come under careful regulatory scrutiny and are subject to severe restrictions. Therefore, advantageous methods for making intermediates are not only advantageous for producing high yields but also are advantageous for producing the intermediate in high purity "as made" so that little, preferably no, further purification is needed. Accordingly, an object of this invention is to provide a method for making DPAP in high yield and high purity.
References U.S. Pat. Nos. 5,102,444 and 5,017,212 disclose the preparation of DPAP and use of same in the preparation of sulfonylurea herbicides, but do not disclose the present invention.